package com.whz.gateway.limit.sentinel;

import lombok.extern.slf4j.Slf4j;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.lang.NonNull;
import org.springframework.stereotype.Component;
import org.springframework.web.reactive.function.BodyInserters;
import org.springframework.web.reactive.function.server.HandlerFunction;
import org.springframework.web.reactive.function.server.ServerRequest;
import org.springframework.web.reactive.function.server.ServerResponse;
import reactor.core.publisher.Mono;

import java.util.Optional;

import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.GATEWAY_ORIGINAL_REQUEST_URL_ATTR;

/**
 * sentinel 拦截的服务降级处理器
 *
 * @author whz
 */
@Slf4j
@Component
public class GatewayFallbackHandler implements HandlerFunction<ServerResponse> {

    @Override
    @NonNull
    public Mono<ServerResponse> handle(@NonNull ServerRequest serverRequest) {
        Optional<Object> originalUris = serverRequest.attribute(GATEWAY_ORIGINAL_REQUEST_URL_ATTR);
        originalUris.ifPresent(originalUri -> log.error("网关执行请求:{},失败,hystrix服务降级处理", originalUri));
        return ServerResponse
                .status(HttpStatus.INTERNAL_SERVER_ERROR.value())
                .contentType(MediaType.APPLICATION_JSON)
                .body(BodyInserters.fromValue("服务异常,请稍后重试"));
    }
}